1. Field of the Invention
The present invention relates to a network based switching system, and more particularly to an audio packet switching system, operated as a single interface when various signaling protocols are introduced, for processing Real-time Transport Protocol (RTP) packet and audio data
2. Background of the Related Art
Real-time Transport Protocol (RTP) is a communication protocol of the transport layer for transmitting and receiving voice or motion pictures in real time. RTP is characterized in that communications are processed between terminals without depending on communication devices such as a router, etc.
Generally, a system for transmitting audio data, such as IP based or network based switching system using the RTP protocol, employs a hard coding method according to a signaling protocol. Hard coding is a method that performs coding depending on the corresponding protocol.
FIG. 1 is a block diagram illustrating a configuration of a related art IP based audio packet switching system.
Referring to FIG. 1, in the related art IP based audio packet switching system, each part includes a signaling protocol 10 for signaling the other part, a Real Time Control Protocol (RTP/RTCP) module 20 for performing the RTP operation between end-points according to the signaling of each of the signaling protocols 10, and an audio coder 30 for compressing and recovering the audio packets.
The switching system, configured as described above, negotiates various pieces of information such as a signal type, an audio coding type, and transmitting point/receiving point, etc., and then operates to open and close a voice path according to a predetermined signal.
The RTP/RTCPs 20 play only a role of transmitting and receiving the audio packets through the voice path, which is connected according to the signaling. The RTP/RTCPs 20 are intended to compress and recover the transmitted and received audio packets using a Digital Signal Processor (DSP).
The functional elements of the related art audio packet switching system are accomplished by the signaling. The RTP operations are limited to the operation of the RTP at both communication end points to transmit and receive the audio/video packets.
The related art switching system and method, however, has various problems. For example, it is difficult to implement a system using various protocols and to manage overall network resources and source codes, because a hard coding method to the corresponding signaling protocol is used. The hard coding effectively prevents other protocols from being used.
If a protocol, such as a standard protocol, H.323, Session Initiation Protocol (SIP), or Media Gateway Control Protocol (MGCP), is used as the signaling protocol, the functional elements of the switching system can be implemented by simple make-ups without causing any problem in signaling, since messages and commands defined at the standard protocol are formed to give the first consideration to signaling.
Since the operations of each protocol are accomplished through a predetermined interface with the RTP in the switching system implemented using the standard protocol, however, overall RTP management with the other protocols becomes difficult. Additionally, operations of the audio coder also become difficult and implementation efficiency of additional functions is reduced.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.